The invention relates to a burner comprising a primary conduit for supplying a mixture of combustible gas and air; and at least one primary mixture chamber, having at least one inflow opening connected with the primary mixture supply conduit, the diameter of which opening is of the same order as that of the primary mixture supply conduit, and at least one primary discharge opening, which discharges into the space surrounding the burner, and the diameter of which is small relative to the diameter of the primary mixture supply conduit.
Such burners are already frequently being used for heating purposes. However, known burners have the drawback, that at high burner loads (when a large amount of mixture is burnt per unit of time) high combustion temperatures occur in the burning mixture. At these high combustion temperatures, large quantities of nitrogen oxide (NOx) are formed.
Furthermore, these known burners have the drawback of only being adjustable over a limited range of loads. Therefore, when used in a heating installation, known burners have to be turned on and off regularly in order to maintain a temperature within a given range. This not only leads to a reduced convenience to the user, but also results in accelerated wear of the heating installation. Furthermore, substances which are damaging to humans and to the environment are emitted every time the burner is turned on or off.
The limited adjustability of the known burners is due to the fact that as burner power is increased by increasing mixture supply, at a certain point the velocity at which the mixture to be burnt discharges from the primary discharge openings exceeds its combustion velocity. Thereby, the flame is "blown away" as it were, and the burner extinguishes.